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changes.mady.by.user WHITE, ADAM JAMES

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  • He dewar bubbler (optional if there is a scale)
    • It is a long ~8ft section of 3/8" SS pipe with a dropper squeezer on the end. On the bubblier are two zip ties or clamps to help tell volume
  • Scale
  • 9/16 open ended wrench
  • 2x adjustable wrenches
  • Balloon grade helium
  • All PPE called out above
  • Heater Gun
  • Ladder
  • Measuring tape

Procedure

You and one other person review the various valves on the stinger

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and helium dewar

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Dewar valves

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Stinger Valves

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If there is already a dewar hooked up to the crysostat start here:

  1. Bring a new dewar down to the hutch that needs the replacement. Do not ride on the elevator with it!
  2. On the stinger in the dewar, spin the needle valve counterclockwise to close the valve.
  3. Turn off the roughing pump that is hooked up to the cryohead.
  4. Close the cylinder that is hooked up to the dewar and isolate it.
  5. Close all valves on the dewar. You will not be able to close the vertical one because the stinger is in it.
  6. Vent the poly line to air that connects the dewar to the helium cylinder and undo the swage fitting on the the dewar side of the poly line.
  7. Open Wearing gloves and a face shield, open the low pressure relief vent valve to vent out the ooliage oolage of the dewar, reading is on the . Keep this open for the remainder of the procedure. Verify that the pressure is dropping on the dewar's gauge.
    1. Keep an eye out for the PRV to freeze over. Use the heat gun to warm up the valve or it up so the pressure relief device to stop them from freezing over.doesn't freezing open.
  8. Once the pressure is ~ 1 psi in the dewar, start Start to unscrew the seal that holds the singer into the dewar. You may have to wiggle it a bit.Once the pressure is gone, deploy a ladder nearby the dewar.
  9. Take off the "Y" manifold on the horzontal vent valve off, break behind the 1/2" SS NPT female thread.
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  10. Deploy a ladder right next to the dewar
  11. Both people need to wear all PPE called out above
  12. One person will climb the ladder and the other stands near the dewar
  13. The person on the ladder will grab the braided hose and near the valves and start to lift up while the person below keeps them lifting straight up and wiggling the stinger.
  14. Once it is fully out of the dewar
  15. Undo the ratcheting straps that tie down the dewar
  16. Remove the ODM